Cylindrical battery

Abstract

The utility model relates to a cylindrical battery. The cylindrical battery comprises a shell, the electrode assembly is arranged in the shell, and the electrode assembly comprises a roll core and a tab; the sealing cover seals the opening of the shell, the side wall of the opening of the shell and the side wall of the sealing cover are fixedly connected through threads, the sealing cover is provided with a thinning area, one side of the thinning area faces the electrode assembly and is connected with the tab, and the other side of the thinning area deviates from the electrode assembly and is exposed outside the shell. The cylindrical battery disclosed by the utility model has the advantages that the internal resistance of the battery is reduced, and the risk that a conventional collector plate is thin and easy to deform is avoided; the contact area and the friction force between the sealing cover and the shell are increased, and the overflowing area is increased, so that the performance and the stability of the battery are improved; bad risks such as membrane scalding, laser leakage, welding explosion points and cracks are avoided; the cylindrical battery is very easy to assemble, and is also convenient to disassemble and maintain when needed.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially is related to a cylindrical battery. BACKGROUND

[0002] Lithium ion battery has high energy density, long cycle life, no memory effect and environmental friendly advantage, is widely used in electric vehicle, electric tool and 3C consumer product field etc. Especially, all tab cylindrical battery is widely welcomed by market in recent years.

[0003] The utility model discloses a kind of all tab cylindrical battery assembly structure, including shell, flow guide convex and cover plate, flow guide convex middle part is outwardly convex pole, the bottom surface of cover plate is set with the accommodation slot for accommodating flow guide convex, the middle part of cover plate is set with the mounting hole for pole to protrude, the inner circumferential side of shell is equipped with first screw thread, the outer circumferential side of cover plate is equipped with second screw thread matched with first screw thread and fixedly connected.The above-mentioned flow guide convex realizes the electrical connection of cylindrical battery, and the above-mentioned cover plate realizes the sealing of cylindrical battery shell.Flow guide convex includes current collector and pole, on the one hand, in the process of battery assembly, flow guide convex needs to be welded with tab first, then cover plate is connected with flow guide convex and shell, and assembly difficulty is higher;On the other hand, since current collector needs to be penetrated and welded, therefore is not very thick, and current collector is easily deformed;And tab is connected with pole by current collector, and battery internal resistance is higher.How to provide a kind of cylindrical battery that assembly is easy and battery performance is better is the technical problem to be solved urgently in the prior art. UTILITY MODEL CONTENTS

[0004] Therefore, the utility model provides a kind of cylindrical battery, assembly is easy and battery performance is good.

[0005] To solve the above technical problems, the utility model provides a kind of cylindrical battery, comprising:

[0006] Shell, the shell is equipped with shell opening in first direction, the sidewall of shell opening is provided with first screw thread, and the axis of first screw thread is parallel with first direction;

[0007] Electrode assembly, the electrode assembly is located in the shell, and the electrode assembly includes roll core and tab, one end of roll core in first direction is connected with tab, and tab is close to shell opening;

[0008] A sealing cover is provided with a second thread on the side wall, the axis of the second thread is parallel to the first direction, the sealing cover seals the shell opening, and the side wall of the shell opening and the side wall of the sealing cover are fixedly connected through the first thread and the second thread, the sealing cover is provided with a thinning area, one side of the thinning area in the first direction faces the electrode assembly and is connected with the tab, and the other side of the thinning area in the first direction is away from the electrode assembly and is exposed outside the shell.

[0009] Further, along the first direction, the surface of the sealing cover away from the electrode assembly is provided with a groove, and the groove bottom is the thinning area.

[0010] Further, the sealing cover is provided with a plurality of thinning areas, the plurality of thinning areas are uniformly arranged around the center of the sealing cover, and the plurality of thinning areas are in one-to-one correspondence with a plurality of groups of tabs.

[0011] Further, the thinning area is a fan ring groove, the sealing cover is provided with a liquid injection hole at the center position, and the center of the plurality of fan ring grooves and the central axis of the liquid injection hole are located at the same position.

[0012] Further, the groove is an annular groove, the sealing cover is provided with a liquid injection hole at the center position, and the central axis of the annular groove and the central axis of the liquid injection hole are arranged in line.

[0013] Further, the side wall of the shell opening and the side wall of the sealing cover are matched with each other and are both stepped side walls, the side wall of the shell opening has a first annular stepped surface, the side wall of the sealing cover has a second annular stepped surface, and the first annular stepped surface is opposite to the second annular stepped surface.

[0014] Further, the cylindrical battery further comprises a sealing gasket, and the sealing gasket is arranged between the first annular stepped surface and the second annular stepped surface.

[0015] Further, the sealing gasket is fixed on the first annular stepped surface, and / or the sealing gasket is fixed on the second annular stepped surface.

[0016] Further, the side wall of the shell opening is an inner side wall, the side wall of the sealing cover is an outer side wall, the outer side wall of the sealing cover further has a third annular stepped surface, the third annular stepped surface is located on the side of the second annular stepped surface away from the electrode assembly, the third annular stepped surface and the second annular stepped surface face the same direction, and the third annular stepped surface is opposite to the end surface of the shell opening.

[0017] Furthermore, along the first direction, the distance between the end of the first thread near the electrode assembly and the end face of the housing opening is greater than the distance between the end of the electrode assembly near the sealing cap and the end face of the housing opening.

[0018] Compared with the prior art, the above-mentioned technical solution of this utility model has the following advantages: The cylindrical battery of this utility model eliminates the current collector and sets a thinning area on the sealing cover for contact with the electrode assembly to realize the current collection function. The sealing cover is fixed to the shell by thread. First, the electrode assembly is directly connected to the sealing cover, which reduces the internal resistance of the battery and avoids the risk of deformation due to the thin thickness of conventional current collectors. Second, the threaded connection between the sealing cover and the shell increases the contact area and friction between the sealing cover and the shell, increasing the current flow area and thus improving the performance and stability of the battery. Third, the conventional current collector is integrated into the sealing cover, eliminating the need for welding of the current collector and avoiding adverse risks such as diaphragm burns, laser leakage, welding explosions, and cracks. Finally, the cylindrical battery is very easy to assemble. Simply tightening the sealing cover into the shell opening achieves the sealing of the shell and the electrical connection with the electrode assembly, and also facilitates the disassembly and maintenance of the battery when needed. Attached Figure Description

[0019] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0020] Figure 1 This is a front sectional view of the cylindrical battery in Embodiment 1 of this utility model and a welding schematic diagram thereof;

[0021] Figure 2 This is a front sectional view of the shell in Embodiment 1 of this utility model;

[0022] Figure 3 This is a front sectional view of the sealing cap in Embodiment 1 of this utility model;

[0023] Figure 4 This is a perspective view of the sealing cap in Embodiment 1 of this utility model;

[0024] Figure 5 This is a perspective view of the sealing cap in Embodiment 2 of this utility model.

[0025] Explanation of reference numerals in the accompanying drawings: 1. Housing; 11. First thread; 12. First annular stepped surface; 13. End face; 2. Electrode assembly; 21. Core; 22. Tab; 3. Sealing cap; 31. Thinning area; 32. Groove; 33. First annular groove wall; 34. Second annular groove wall; 35. Second thread; 36. Second annular stepped surface; 37. Third annular stepped surface; 38. Injection hole; 4. Sealing gasket; 5. Annular gap. DETAILED DESCRIPTION

[0026] The utility model will be further described below in connection with the drawings and specific embodiments, so that those skilled in the art can better understand the utility model and can be implemented, but the embodiment is not as the limitation of the utility model. Embodiment one

[0027] Referring to Figures 1 to 4 An embodiment of the cylindrical battery provided by the utility model is shown.

[0028] The cylindrical battery comprises:

[0029] The shell 1 is provided with a shell opening in the first direction, and a first thread 11 is arranged on the side wall of the shell opening, and the axis of the first thread 11 is parallel to the first direction.

[0030] The electrode assembly 2 is arranged in the shell 1, and the electrode assembly 2 comprises a winding core 21 and a tab 22, one end of the winding core 21 in the first direction is connected to the tab 22, and the tab 22 is close to the shell opening.

[0031] The sealing cover 3 is provided with a second thread 35 on the side wall, the axis of the second thread 35 is parallel to the first direction, the sealing cover 3 seals the shell opening, and the side wall of the shell opening and the side wall of the sealing cover are connected and fixed through the first thread 11 and the second thread 35, the sealing cover 3 is provided with a thinning area 31, one side of the thinning area 31 in the first direction faces the electrode assembly 2 and is connected to the tab 22, and the other side of the thinning area 31 in the first direction is away from the electrode assembly 2 and is exposed outside the shell 1.

[0032] The shell 1 is a cylindrical shell, the first direction is the axial direction of the cylindrical shell, and the shell opening penetrates one end face in the axial direction of the cylindrical shell; the winding core 21 is a cylindrical winding core wound into the shell 1, and the winding core 21 leads out the above-mentioned tab 22 from one end of the shell opening; the second thread 35 on the sealing cover 3 is tightly matched with the first thread 11 on the shell 1. Part of the sealing cover 3 is provided as a thinning area 31, the size of the body of the sealing cover 3 along the first direction is greater than the size of the thinning area 31 along the first direction, the second thread 35 is arranged on the body of the sealing cover 3, the size of the thinning area 31 along the first direction is configured to be able to be penetrated and welded along the first direction, the body of the sealing cover 3 and the thinning area 31 both have opposite inner surfaces and outer surfaces in the first direction, the inner surface of the thinning area 31 faces and connects the tab 22, the outer surface of the thinning area 31 faces away from the tab 22 and is located outside the shell 1, that is, the outer surface of the thinning area 31 can be contacted outside the shell 1, therefore, after the sealing cover 3 is connected to the shell 1, the penetration welding of the thinning area 31 and the tab 22 can be realized by contacting the outer surface of the thinning area 31 with a welding head outside the shell 1, and the size of the body of the sealing cover 3 along the first direction is configured to at least meet the mechanical strength requirement of the sealing cover 3.

[0033] In the process of assembling the cylindrical battery, the electrode assembly 2 is first put into the shell 1 from the shell opening, so that the tab 22 of the electrode assembly 2 faces the shell opening; then the sealing cover 3 is threadedly connected to the shell 1, so that the tabs 22 can all contact the thinning area 31; and then the thinning area 31 and the tab 22 are welded, and the shell 1 and the sealing cover 3 are welded.

[0034] In the above-mentioned cylindrical battery, the current collecting disc is cancelled, the thinning area 31 is arranged on the sealing cover 3, and the sealing cover 3 is threadedly connected and fixed to the shell 1, so that the electrode assembly 2 is directly connected to the sealing cover 3, the battery internal resistance is reduced, and the risk of deformation of the conventional current collecting disc with a relatively thin thickness is avoided; secondly, the sealing cover 3 is threadedly connected to the shell 1, the contact area and friction force between the sealing cover 3 and the shell 1 are increased, the overcurrent area is increased, and the performance and stability of the battery are improved; thirdly, the conventional current collecting disc is integrated on the sealing cover 3, the welding of the current collecting disc is not needed, and the risks of film scalding, laser leakage, welding craters, cracks and the like are avoided; and finally, the cylindrical battery is very easy to assemble, as long as the sealing cover 3 is screwed on the shell opening, the sealing of the shell 1 and the electrical connection with the electrode assembly 2 can be realized, and the battery is convenient to disassemble and maintain when needed.

[0035] In the embodiment, along the above-mentioned first direction, the surface of the above-mentioned sealing cover 3 facing away from the above-mentioned electrode assembly 2 has a groove 32, and the groove bottom of the above-mentioned groove 32 is the above-mentioned thinning area 31.

[0036] Since the inner surface of the thinning area 31 needs to be connected with the tab 22 of the electrode assembly 2, the inner surface of the thinning area 31 is preferably arranged to protrude or flush with the inner surface of the body of the sealing cover 3, and thus the outer surface of the thinning area 31 needs to be arranged to be recessed into the outer surface of the body of the sealing cover 3. Specifically, the thinning area 31 and the body of the sealing cover 3 can be a split structure, and preferably an integral structure, and it is necessary to ensure that the thinning area 31 and the body of the sealing cover 3 are connected as an integral body before being connected to the case 1.

[0037] By forming a groove 32 on the surface of the sealing cover 3 away from the electrode assembly 2, the groove bottom of the groove 32 can be a required thinning area 31, the inner surface of the thinning area 31 flushes with the inner surface of the body of the sealing cover 3, and the outer surface of the thinning area 31 is recessed into the outer surface of the body of the sealing cover 3, which not only ensures the contact of the thinning area 31 with the tab 22, but also ensures the thin thickness of the thinning area 31 to enable penetration welding. Moreover, the groove 32 can serve as a driving hole for driving the rotation of the sealing cover 3, and a special tool is used to extend into the groove 32 to fix the sealing cover 3, and the tool is rotated and pressed to drive the sealing cover 3 to rotate into the case 1. After the sealing cover 3 is locked with the case 1, the tool is pulled out.

[0038] In the embodiment, the sealing cover 3 is provided with a plurality of thinning areas 31, and the plurality of thinning areas 31 are arranged uniformly around the center of the sealing cover 3, and the plurality of thinning areas 31 are in one-to-one correspondence with a plurality of groups of tabs 22.

[0039] The greater the area of the thinning area 31 of the sealing cover 3 and the smaller the body part, the worse the mechanical strength of the sealing cover 3, and the smaller the area of the thinning area 31 of the sealing cover 3 and the larger the body part, the better the mechanical strength of the sealing cover 3. Therefore, while ensuring the connection of the tab with the thinning area 31, the area of the thinning area 31 should be as small as possible.

[0040] The tab leading end of the cylindrical core leads out a plurality of groups of tabs 22, and the plurality of groups of tabs 22 are arranged uniformly around the central axis of the cylindrical core, and the different groups of tabs 22 are spaced apart by a certain distance, so that the local position of the tab leading end of the cylindrical core leads out the tab 22. The thinning area 31 only needs to be able to contact the tab 22. It should be noted that in order to enable the tab 22 to contact the thinning area 31, the orthogonal projection of the plurality of groups of tabs 22 of the electrode assembly 2 on the projection plane in the first direction falls on the orthogonal projection of the plurality of thinning areas 31 of the sealing cover 3 on the same projection plane.

[0041] By arranging the thinning area 31 as a plurality of thinning areas 31, the plurality of thinning areas 31 are in one-to-one correspondence with a plurality of groups of tabs 22 of the electrode assembly 2, on the one hand, it ensures that the tab 22 can contact the thinning area 31, and on the other hand, the area of the thinning area 31 of the sealing cover 3 is as small as possible, which can ensure the mechanical properties of the sealing cover 3.

[0042] In the embodiment, the groove 32 is a fan-shaped ring groove, the sealing cover 3 is provided with a liquid injection hole 38 at the center position, and the centers of the plurality of fan-shaped ring grooves are located at the same position as the central axis of the liquid injection hole 38.

[0043] The groove 32 is a fan-shaped ring groove, and the groove bottom of the groove 32 is also a fan-shaped ring, that is, the thinning area 31 is fan-shaped.

[0044] Each group of the tab 22 of the cylindrical battery is generally fan-shaped, and therefore, the shape of the thinning area 31 and the tab 22 is matched, and the area of the thinning area 31 of the sealing cover 3 is minimized under the premise that the tab 22 can contact the thinning area 31.

[0045] In the embodiment, the side wall of the shell opening and the side wall of the sealing cover 3 are matched and are both stepped side walls, the side wall of the shell opening has a first annular stepped surface 12, the side wall of the sealing cover 3 has a second annular stepped surface 36, and the first annular stepped surface 12 is opposite to the second annular stepped surface 36.

[0046] The side wall of the shell opening includes two circumferential surfaces in the first direction, the diameters of the two circumferential surfaces are different, and the first annular stepped surface 12 is formed between the two circumferential surfaces and faces the outside of the shell 1; the side wall of the sealing cover 3 includes two circumferential surfaces in the first direction, the diameters of the two circumferential surfaces are different, and the second annular stepped surface 36 is formed between the two circumferential surfaces and faces the first annular stepped surface 12.

[0047] By matching the side wall of the shell opening and the side wall of the sealing cover 3 and making them both stepped side walls, the gap formed between the shell 1 and the sealing cover 3 has a certain turning, and the shell 1 and the sealing cover 3 are not easy to leak.

[0048] In the embodiment, the cylindrical battery further includes a sealing gasket 4, and the sealing gasket 4 is arranged between the first annular stepped surface 12 and the second annular stepped surface 36.

[0049] Since the shell 1 of the cylindrical battery needs to be sealed after being connected with the sealing cover 3, the sealing gasket 4 is arranged between the first annular stepped surface 12 of the shell 1 and the second annular stepped surface 36 of the sealing cover 3, and the sealing gasket 4 is made of elastic material.

[0050] On one hand, the sealing gasket 4 can seal the gap between the shell 1 and the sealing cover 3, so that the shell 1 and the sealing cover 3 cannot leak. On the other hand, the shell 1 and the sealing cover 3 inevitably have a fit tolerance in the first direction. The sealing gasket 4 can compensate for the fit tolerance of the shell 1 and the sealing cover 3 in the first direction. In addition, the sealing gasket 4 is arranged between the first annular stepped surface 12 and the second annular stepped surface 36, so that the sealing gasket 4 is easy to install.

[0051] In the embodiment, the sealing gasket 4 is fixed to the first annular stepped surface 12 and / or the second annular stepped surface 36.

[0052] The sealing gasket 4 is annular. If it is directly placed between the first annular stepped surface 12 and the second annular stepped surface 36, on one hand, it is difficult to ensure that they are centered. On the other hand, the sealing gasket is easy to fall off during the assembly of the cylindrical battery. Therefore, it is better to fix the sealing gasket 4. Specifically, a sealing clamping groove can be arranged on the first annular stepped surface 12 and / or the second annular stepped surface 36. The sealing clamping groove is annular, and the sealing gasket 4 is embedded in the sealing clamping groove.

[0053] By arranging the sealing gasket 4 to be relatively fixed to the first annular stepped surface 12 and / or the second annular stepped surface 36, the sealing gasket 4 is easy to position, and the centering of the sealing gasket 4, the first annular stepped surface 12 and the second annular stepped surface 36 is ensured.

[0054] In the embodiment, the side wall of the shell opening is an inner side wall, the side wall of the sealing cover is an outer side wall, the outer side wall of the sealing cover 3 further has a third annular stepped surface 37, the third annular stepped surface 37 is located on the side of the second annular stepped surface 36 away from the electrode assembly, the third annular stepped surface 37 and the second annular stepped surface 36 face the same direction, and the third annular stepped surface 37 is opposite to the end surface 13 of the shell opening.

[0055] The sealing cover 3 is provided with the second annular stepped surface 36 and the third annular stepped surface 37. The second annular stepped surface 36 cooperates with the first annular stepped surface 12 on the inner side wall of the shell opening, and the third annular stepped surface 37 cooperates with the end surface of the shell opening. On one hand, the gap formed between the shell 1 and the sealing cover 3 has more turns, and the sealing performance between the sealing cover 3 and the shell 1 is better. On the other hand, the end surface of the shell opening can limit the sealing cover 3, so that the sealing cover 3 cannot be screwed into the shell 1 without limit, thereby preventing excessive extrusion on the electrode assembly 2. In addition, the annular gap 5 is formed between the outer side wall of the shell opening and the outer side wall of the sealing cover 3. The annular gap 5 is located on the side of the cylindrical battery. The annular gap 5 between the sealing cover 3 and the shell 1 is welded from the side of the cylindrical battery. Compared with the conventional structure welded from the top of the cylindrical battery, there is no risk of laser leakage.

[0056] In the embodiment, along the first direction, the distance between the end of the first thread 11 close to the electrode assembly 2 and the end face of the shell opening is greater than the distance between the end of the electrode assembly 2 close to the sealing cover 3 and the end face of the shell opening.

[0057] The thinning area 31 needs to ensure that it can contact the tab 22. By setting the positional relationship between the first thread 11, the tab 22, and the end face of the shell opening, it is ensured that the thinning area 31 can contact the tab 22.

[0058] In the embodiment, the shell 1 is made of high-strength and corrosion-resistant stainless steel material to ensure the strength and durability of the steel shell. The sealing cover 3 is made of copper alloy material with good electrical conductivity and high strength, and is surface treated to improve corrosion resistance and electrical conductivity. High-precision numerical control machining equipment is used to machine the first thread 11 on the shell 1, and the internal thread is machined according to the design requirements to ensure that the size accuracy, shape accuracy, and surface roughness of the thread meet the requirements. The second thread 35 is machined on the sealing cover 3 by turning or rolling process to ensure the fitting accuracy of the first thread 11 and the second thread 35. The first thread 11 and the second thread 35 are preferably pipe threads with a tooth profile angle of 60°.

[0059] The following are the specific dimensions of several key parts of the cylindrical battery.

[0060] The shell wall thickness of the shell 1 is T1, T1=0.4±0.05mm.

[0061] The radial dimension of the second annular step surface 36 is T2, T2=0.15±0.05mm;

[0062] The height of the first thread 11 and the second thread 35 is T3, T3=0.1±0.05mm;

[0063] The distance between the highest point of the electrode assembly 2 after locking and the lowest point of the first thread 11 is d1, d1>0;

[0064] The thickness of the thinning area 31 along the first direction is d2, d2=0.35~0.6mm, preferably 0.5±0.1mm,

[0065] The height of the lowermost circumferential surface of the sealing cover 3 is d2+d3, d2+d3≥0.8mm, preferably 1±0.1mm;

[0066] The height of the middle circumferential surface of the sealing cover 3 is d4, d4>0.36mm, preferably 0.5±0.05mm;

[0067] The height of the uppermost circumferential surface of the sealing cover 3 is d5, d5≥0.1mm, preferably 0.2mm. Embodiment Two

[0068] Referring to Figure 5 Another embodiment of the cylindrical battery is shown in the utility model.

[0069] The rest is the same as example one, the difference is that the above-mentioned groove 32 is an annular groove, the center of the sealing cover 3 is provided with a liquid injection hole 38, the central axis of the annular groove and the central axis of the liquid injection hole 38 are arranged in line.

[0070] The groove 32 is an annular groove, and the above-mentioned thinning area 31 is an annular thinning area, therefore, the tab 22 can be in contact with the annular thinning area when the sealing cover 3 is rotated to any angle. After the cylindrical battery is assembled, electrolyte is injected into the shell through the above-mentioned liquid injection hole 38. In this embodiment, the groove bottom of the annular groove is a polygonal ring, and the annular groove has opposite first and second annular groove walls 33 and 34. The first and second annular groove walls 33 and 34 are prismatic side surfaces. The annular groove can be matched with a tool for driving the sealing cover 3 to rotate, so as to facilitate the tightening of the sealing cover 3 on the shell 1.

[0071] In the above-mentioned cylindrical battery, the groove 32 is an annular groove, which ensures that the sealing cover 3 can be rotated to any angle, and the tab 22 of the electrode assembly 2 can be electrically connected to the thinning area 31.

[0072] Obviously, the above-mentioned embodiments are only examples for the purpose of clear illustration, and are not limited to the embodiments. For ordinary skilled persons in the art, other different forms of changes or variations can be made on the basis of the above-mentioned description. It is not necessary and impossible to enumerate all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the utility model.

Claims

1. A cylindrical battery, characterized in that, include: The housing (1) has an opening in a first direction, and a first thread (11) is provided on the side wall of the opening, the axis of the first thread (11) being parallel to the first direction. Electrode assembly (2), the electrode assembly (2) is disposed inside the housing (1), the electrode assembly (2) includes a core (21) and a tab (22), one end of the core (21) is connected to the tab (22) in the first direction, and the tab (22) is close to the opening of the housing; A sealing cap (3) is provided with a second thread (35) on its side wall. The axis of the second thread (35) is parallel to the first direction. The sealing cap (3) seals the opening of the housing and the side wall of the opening of the housing is connected and fixed to the side wall of the sealing cap through the first thread (11) and the second thread (35). The sealing cap (3) is provided with a thinning area (31). One side of the thinning area (31) in the first direction faces the electrode assembly (2) and is connected to the tab (22). The other side of the thinning area (31) in the first direction faces away from the electrode assembly (2) and is exposed to the outside of the housing (1).

2. The cylindrical battery according to claim 1, characterized in that, Along the first direction, the sealing cap (3) has a groove (32) on the surface opposite to the electrode assembly, and the bottom of the groove (32) is the thinning area (31).

3. The cylindrical battery according to claim 2, characterized in that, The sealing cover (3) is provided with a plurality of thinning areas (31), which are evenly distributed around the center of the sealing cover (3), and the plurality of thinning areas (31) are in contact with a plurality of tabs (22) in a one-to-one correspondence.

4. The cylindrical battery according to claim 3, characterized in that, The thinning area (31) is a fan-shaped annular groove, and the sealing cap (3) has an injection hole (38) at the center. The center of the multiple fan-shaped annular grooves is located at the same position as the central axis of the injection hole (38).

5. The cylindrical battery according to claim 2, characterized in that, The groove (32) is an annular groove, and the sealing cap (3) has an injection hole (38) at its center. The central axis of the annular groove is collinear with the central axis of the injection hole (38).

6. The cylindrical battery according to claim 1, characterized in that, The sidewall of the housing opening and the sidewall of the sealing cover (3) are matched and are both stepped sidewalls. The sidewall of the housing opening has a first annular step surface (12), and the sidewall of the sealing cover (3) has a second annular step surface (36). The first annular step surface (12) and the second annular step surface (36) are opposite to each other.

7. The cylindrical battery according to claim 6, characterized in that, The cylindrical battery also includes a sealing gasket (4), which is disposed between the first annular step surface (12) and the second annular step surface (36).

8. The cylindrical battery according to claim 7, characterized in that, The sealing gasket (4) is fixed on the first annular step surface (12), and / or the sealing gasket (4) is fixed on the second annular step surface (36).

9. The cylindrical battery according to claim 6, characterized in that, The sidewall of the housing opening is the inner sidewall, and the sidewall of the sealing cover is the outer sidewall. The outer sidewall of the sealing cover (3) also has a third annular step surface (37). The third annular step surface (37) is located on the side of the second annular step surface (36) away from the electrode assembly. The third annular step surface (37) and the second annular step surface (36) face the same direction. The third annular step surface (37) is opposite to the end face (13) of the housing opening.

10. The cylindrical battery according to claim 1, characterized in that, Along the first direction, the distance between the end of the first thread (11) near the electrode assembly (2) and the end face of the housing opening is greater than the distance between the end of the electrode assembly (2) near the sealing cap (3) and the end face of the housing opening.

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